Validate PGXNTOOL_VERIFY_RESULTS_MODE

HISTORY.asc

@@ -90,6 +90,12 @@ command, to any value; `\include` and `\include_relative` count as including `ps
 `test/install/*.out` was never really compared against anything, and is
 rewritten by every run, it's now gitignored -- stop committing it.
 
+== Reject invalid `PGXNTOOL_VERIFY_RESULTS_MODE` values
+Any value other than exactly `pgtap` silently selected `diffs` mode, so a
+typo like `pgTap` quietly weakened the `make results` safeguard. The value
+is now case-insensitive, and anything other than `pgtap` or `diffs` is a
+hard `make` error.
+
 == Guarantee `test/install/*.sql` ordering
 Install files now always run in byte-value (ASCII) filename order,
 regardless of filesystem or locale. If one install file depends on another,

README.asc

@@ -272,7 +272,7 @@ IMPORTANT: *`make results` requires manual verification first*. The correct work
 Never run `make results` without first verifying the test changes are correct. The `results` target copies files from `test/results/` to `test/expected/`, so running it blindly will make incorrect output become the new expected behavior.
 
 ==== verify-results safeguard
-By default, `make results` will refuse to run if your tests are failing, so you can't accidentally promote incorrect output into the new expected results. Which failures it looks for is controlled by `PGXNTOOL_VERIFY_RESULTS_MODE`:
+By default, `make results` will refuse to run if your tests are failing, so you can't accidentally promote incorrect output into the new expected results. Which failures it looks for is controlled by `PGXNTOOL_VERIFY_RESULTS_MODE`, which must be one of these two values (case-insensitive; anything else is a hard `make` error):
 
 `pgtap` (the default):: Scans `test/results/*.out` for pgTAP `not ok` lines (ignoring `# TODO` items) and plan-count mismatches, then also checks `test/regression.diffs` for any output mismatch pgTAP itself wouldn't catch. A test that has no expected output file yet is the one exception: it always shows up in `regression.diffs` (pgxntool creates an empty expected file for it, because `pg_regress` aborts on a missing one), so `make results` is allowed to create its first expected output — provided its own pgTAP output is clean and free of SQL errors. If a new test legitimately needs output containing a SQL error blessed, use `PGXNTOOL_ENABLE_VERIFY_RESULTS=no` for that one run.
 `diffs`:: Only checks whether `test/regression.diffs` exists, so it can't create a new test's first expected output; use `pgtap` mode, or `PGXNTOOL_ENABLE_VERIFY_RESULTS=no` for that one run.
@@ -786,7 +786,7 @@ Default: `$(TESTDIR)`. Directory `pg_regress` writes actual test output to -- `$
 
 === PGXNTOOL_VERIFY_RESULTS_MODE
 
-Default: `pgtap`. Controls how the <<_verify_results_safeguard,verify-results safeguard>> decides whether tests are failing.
+Default: `pgtap`. Controls how the <<_verify_results_safeguard,verify-results safeguard>> decides whether tests are failing. Must be `pgtap` or `diffs` (case-insensitive) when given explicitly; any other value, including an empty one, is a hard `make` error.
 
 ==== pgtap
 

README.html

@@ -1082,7 +1082,7 @@ <h3 id="_results"><a class="anchor" href="#_results"></a><a class="link" href="#
 <div class="sect3">
 <h4 id="_verify_results_safeguard"><a class="anchor" href="#_verify_results_safeguard"></a><a class="link" href="#_verify_results_safeguard">4.7.1. verify-results safeguard</a></h4>
 <div class="paragraph">
-<p>By default, <code>make results</code> will refuse to run if your tests are failing, so you can&#8217;t accidentally promote incorrect output into the new expected results. Which failures it looks for is controlled by <code>PGXNTOOL_VERIFY_RESULTS_MODE</code>:</p>
+<p>By default, <code>make results</code> will refuse to run if your tests are failing, so you can&#8217;t accidentally promote incorrect output into the new expected results. Which failures it looks for is controlled by <code>PGXNTOOL_VERIFY_RESULTS_MODE</code>, which must be one of these two values (case-insensitive; anything else is a hard <code>make</code> error):</p>
 </div>
 <div class="dlist">
 <dl>
@@ -2118,7 +2118,7 @@ <h3 id="_testout"><a class="anchor" href="#_testout"></a><a class="link" href="#
 <div class="sect2">
 <h3 id="_pgxntool_verify_results_mode"><a class="anchor" href="#_pgxntool_verify_results_mode"></a><a class="link" href="#_pgxntool_verify_results_mode">8.9. PGXNTOOL_VERIFY_RESULTS_MODE</a></h3>
 <div class="paragraph">
-<p>Default: <code>pgtap</code>. Controls how the <a href="#_verify_results_safeguard">verify-results safeguard</a> decides whether tests are failing.</p>
+<p>Default: <code>pgtap</code>. Controls how the <a href="#_verify_results_safeguard">verify-results safeguard</a> decides whether tests are failing. Must be <code>pgtap</code> or <code>diffs</code> (case-insensitive) when given explicitly; any other value, including an empty one, is a hard <code>make</code> error.</p>
 </div>
 <div class="sect3">
 <h4 id="_pgtap"><a class="anchor" href="#_pgtap"></a><a class="link" href="#_pgtap">8.9.1. pgtap</a></h4>
@@ -2217,7 +2217,7 @@ <h2 id="_copyright"><a class="anchor" href="#_copyright"></a><a class="link" hre
 </div>
 <div id="footer">
 <div id="footer-text">
-Last updated 2026-10-07 16:35:22 -0500
+Last updated 2026-10-07 16:52:43 -0500
 </div>
 </div>
 </body>

base.mk

@@ -89,6 +89,15 @@ pgxntool_validate_yesno = $(strip \
     $(shell echo "$(1)" | tr '[:upper:]' '[:lower:]'),\
     $(error $(2) must be "yes" or "no", got "$(1)")))
 
+# Helper function: normalize a single-word variable to lowercase and validate
+# it against a list of allowed values.
+# Usage: $(call pgxntool_validate_choice,VALUE,VARIABLE_NAME,ALLOWED_VALUES)
+# Returns the lowercase value, or errors if it isn't exactly one of ALLOWED_VALUES.
+pgxntool_validate_choice = $(strip \
+  $(if $(and $(filter 1,$(words $(1))),$(filter $(3),$(shell echo "$(1)" | tr '[:upper:]' '[:lower:]'))),\
+    $(shell echo "$(1)" | tr '[:upper:]' '[:lower:]'),\
+    $(error $(2) must be one of: $(3); got "$(1)")))
+
 # ------------------------------------------------------------------------------
 # test-build: Sanity check extension files before running full test suite
 # ------------------------------------------------------------------------------
@@ -288,6 +297,8 @@ _CHECK_TEST_INSTALL_ERROR_STOP_SCRIPT ?= $(PGXNTOOL_DIR)/test/bin/check-test-ins
 #
 # Variable: PGXNTOOL_VERIFY_RESULTS_MODE
 #   - Controls how verify-results detects test failures
+#   - Allowed values: "pgtap" or "diffs" (case-insensitive); anything else,
+#     including an empty value, is a parse-time error
 #   - "pgtap" (default): scans test/results/*.out for "not ok" lines and plan
 #     mismatches (TAP failures). Also checks regression.diffs as a fallback.
 #     Use this mode when your test suite uses pgTap.
@@ -306,6 +317,7 @@ endif
 
 # Default mode: pgtap (scans results/*.out for TAP failures)
 PGXNTOOL_VERIFY_RESULTS_MODE ?= pgtap
+override PGXNTOOL_VERIFY_RESULTS_MODE := $(call pgxntool_validate_choice,$(PGXNTOOL_VERIFY_RESULTS_MODE),PGXNTOOL_VERIFY_RESULTS_MODE,pgtap diffs)
 
 # ------------------------------------------------------------------------------
 # check-stale-expected: catch orphaned/unexpected test/expected/ files